3D analysis of 643 modern and ancient dog and wolf skulls reveals recognisably domestic cranial diversity by at least 11,000 years ago, near the end of the last Ice Age. Mesolithic and Neolithic dogs accounted for roughly half of the cranial variation seen in modern dogs, though extreme modern skull shapes (such as those of pugs or bulldogs) were absent. The findings suggest that major morphological diversification largely predates recent breed formation and reflects long-standing ecological and cultural influences across Eurasia.
Ancient Origins: Dog Size and Shape Diversity Began at Least 11,000 Years Ago, Study Shows
3D analysis of 643 modern and ancient dog and wolf skulls reveals recognisably domestic cranial diversity by at least 11,000 years ago, near the end of the last Ice Age. Mesolithic and Neolithic dogs accounted for roughly half of the cranial variation seen in modern dogs, though extreme modern skull shapes (such as those of pugs or bulldogs) were absent. The findings suggest that major morphological diversification largely predates recent breed formation and reflects long-standing ecological and cultural influences across Eurasia.
06:29 AM, 11/14/2025Science
Dog diversity is far older than modern breeds
New research shows that the remarkable variety of dog shapes and sizes we see today began long before modern breed-making. Three-dimensional analyses of 643 skulls — including modern and ancient dogs and wolves dating back roughly 50,000 years — reveal recognisably domestic skull forms by at least 11,000 years ago, near the end of the last Ice Age.
What the study examined
The international team compared 3D models of 158 modern dog skulls, 86 modern wolf skulls, 281 ancient dog skulls and 118 ancient wolf skulls. Using geometric and morphological analyses, they tracked changes in cranial shape and size through time and across regions. Notably, three skulls from the Veretye archaeological site in Russia showed domestic morphologies dating to about 11,000 years ago.
Key findings
Early diversification: Dogs became proportionally shorter and broader in the skull compared with wolves soon after diverging from an ancient wolf population, and substantial cranial variation existed in prehistoric dog populations.
Significant but not extreme: While extreme skull shapes characteristic of some modern breeds (for example, bulldogs or pugs) were not observed in the archaeological sample, Mesolithic and Neolithic dogs already represented roughly half of the cranial diversity seen in modern dogs.
“Our study shows that substantial cranial diversification was already well established during prehistory,” said bioarchaeologist Allowen Evin of the University of Montpellier and CNRS, co-lead author of the paper published in Science.
Context and caveats
The authors emphasize that the archaeological record does not translate directly into modern breeds: the formal concept of a 'breed' is recent, and the analysis focused only on skull morphology. The study did not assess coat color, body proportions or behavior, so it cannot assign archaeological specimens to named modern breeds.
Dogs were the first animals domesticated by humans, descending from an ancient wolf population distinct from today's wolves. Over millennia humans selected dogs for varied functional roles — hunting, herding, guarding, sledding — driving regional morphological differences. In the last few centuries, kennel clubs and aesthetic preferences further intensified and formalized breed distinctions.
Why this matters
These results shift our understanding of when and how dog diversity developed. Rather than being mainly a product of recent selective breeding, much of the foundational cranial variation among dogs was already present in prehistoric populations across Eurasia, reflecting long-standing ecological and cultural influences on early dog lineages.
Study citation: Allowen Evin et al., published in Science. Reporting by Will Dunham; editing by Daniel Wallis.